Today in Tech: Twitter launching photo service?

Fortune’s curated selection of the holiday weekend’s most newsworthy tech stories from all over the Web. Sign up to get the newsletter delivered to you every day.

* Twitter reportedly plans to launch a photo-sharing service at All Things D’s D9 conference this Wednesday. If it takes off, the service would mark a major step forward for the social network as users currently have to store their photos on third-party sites like Twitpic and Flickr. (All Things D)

* ARM, which licenses its processor designs to companies for use in popular mobile products like the iPad and Samsung’s Galaxy Tab tablet, predicts its chips will be found in over half of tablets, smart phones, and other similarly-handy devices by 2015. (Its share currently comes in at 10%.) (PC World)

* Intelunveiled some of its future plans including what it’s dubbed “Ultrabooks,” a potentially affordable, lightweight Ivy Bridge chipset-powered PC laptop class the company hopes will up catch on and make up 40% of the PC market by the end of 2012. As for its Atom chips, found mostly in netbooks, expect their already wee size to get shrunken down every year moving forward, starting with Cedar Trail, promising 10 hours of battery life in between charges. (Engadget)

* Airbnb, the growing start-up that lets people rent out other people’s apartments in lieu of hotel rooms, is reportedly rounding up another $100 million in funding at a valuation of $1 billion, this time led by venture capital firm Andreessen Horowitz. (TechCrunch)

* Has Android’s lead over Apple’s iOS stopped growing? That’s what the latest numbers from Nielsen seem to indicate. From February to April 2011, Google’s numbers in that department held steady — no less, no more — while Apple’s did the same. (Fortune)

* How photo-sharing service Instagramhas the potential to become “the mobile social hub.” (GigaOm)